Hi all, this is a completely reworked submission of the imx-irqsteer driver. The first version was bugged due to wrong/misleading documentation and buggy implementation of the downstream driver that only worked correctly with a very specific DT configuration.
The key information here is that a given SoC can have multiple instances of the irqsteer controller, which can be connected to mutiple output IRQ lines, but all the input IRQs to one instance are exclusively steered to one of the output IRQs (which is called a channel). So it's a flexible hardware design, were each irqsteer instance needs to be told which upstream IRQ it should use, instead of this being fixed at SoC design time. Also the controller is configurable in the number of input IRQs supported, but only in groups of 64 IRQs, which has an influence on the register layout, as status, mask and force registers are packed together. Currently existing implementations of the irqsteer block have between 1 and 8 IRQ groups, which the documentation confusingly also calls a channel. Also there is no per-groups status indication, but only a global status bit, so the IRQ handling can not be optimized, but all status registers must be checked. After figuring out all those bits, the driver turned out to be pretty simple. Regards, Lucas Lucas Stach (2): dt-bindings: irq: add binding for Freescale IRQSTEER multiplexer irqchip: add driver for imx-irqsteer controller .../interrupt-controller/fsl,irqsteer.txt | 34 +++ drivers/irqchip/Kconfig | 8 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-imx-irqsteer.c | 269 ++++++++++++++++++ 4 files changed, 312 insertions(+) create mode 100644 Documentation/devicetree/bindings/interrupt-controller/fsl,irqsteer.txt create mode 100644 drivers/irqchip/irq-imx-irqsteer.c -- 2.19.1